1. Field of the Invention
This invention relates to improved water closet flushing devices, and more particularly to flush control devices in tank-type water closets.
2. The Prior Art
Millions of gallons of water are needlessly wasted every day through the use of conventional tank-type water closets. These water closets are designed to rapidly release a large quantity of water (about 31/2 to 4 gallons or 13.75 to 15.14 liters) into the bowl of the water closet each time the flush handle is depressed. The force of such a quantity of water moving at the resulting velocity and flow rate enables a complete flushing of the contents of the bowl. However, this large quantity of water is not always needed to adequately flush the bowl.
For example, when flushing liquid waste as opposed to solid waste material, adequate flushing can be accomplished when using only 11/2 to 2 gallons of water (5.68 to 7.51 liters), or about half the quantity of water which is normally used. As can be appreciated, by releasing a full tank of water each time a water closet is flushed, much water is needlessly wasted.
In an attempt to eliminate the unnecessary use of water when flushing a water closet, the prior art has developed two general concepts for providing plural level flush volumes in a water closet. One is the concept of plural level flush drains. Generally, devices of the type require complete removal or considerable modification of the drain plug assembly to accommodate installation of elaborate elongated donut-type float-valve cylinder and lid assemblies. See, for example, applicant's prior patent, U.S. Pat. No. 3,839,747. These types of devices also require modification of the flush handle lifting arm or the placement of stabilizing stop brackets on the water tank standpipe. Furthermore, once installed, no adjustment of the flush level within the water tank can be achieved to provide any variation in the fractional amount of water released when flushing the water closet in a fractional flush mode. These devices likewise provide no clear-cut distinction for the user between depression of the flush handle for a fractional flush and for a full flush. In order to use the water closet in the full flush mode, the user is required to hold the handle in a depressed position for a certain period of time before continued depression of the handle will allow a full flush, resulting in considerable inconvenience.
The other concept generally taught in the prior art involves selective weighting of the drain plug assembly. Generally, in devices of this type, one or more cup or sieve type structures is attached to the drain plug assembly. The additional weight forces the drain plug to reseat before a full flush is completed. While devices of this type offer the advantage of permitting adjustment within the water tank of the fractional flush volume, the other disadvantages of the plural level devices discussed above are also inherent in this type of device, e.g. difficulty of installation, drain plug assembly modification, and delay requirement to achieve a full flush. Moreover, to adjust the water level for a fractional flush in the weighted devices, several adjustments usually must be made which require removal and replacement of parts that are in inaccessible areas.
Because of the above-noted problems and disadvantages in these prior art concepts, the public has been reluctant to put them to use. Accordingly, it would be an improvement in the art to provide a plural level flush control device which may be easily installed in a conventional water closet, with little or no alteration of existing flush handles, lifting arms, or drain plug assemblies. It would also be an improvement over the art to provide for broad flexibility in varying the quantity of water releasable during a fractional flush, and to enable the operator to easily make the desired variations without removing and replacing the device. It would be yet a further improvement over the art to provide a plural level flush control device which distinctly differentiates the fractional flush mode from the full flush mode for the user so as to eliminate any inconvenient waiting period.